Buquet-Fagot C, Fagot D, Mester J
INSERM U.55, Paris, France.
J Cell Physiol. 1993 Apr;155(1):204-9. doi: 10.1002/jcp.1041550126.
In the chemically transformed mouse fibroblasts (BP-A31) placed in a serum-free medium, the cdc2 mRNA content decreases in parallel with the cessation of [3H]thymidine incorporation. Extinction of the cdc2 gene expression is also observed in BP-A31 cells overexpressing the human c-myc oncogene. At quiescence, the cdc2 gene expression can be reinduced with serum or with other mitogens such as insulin or 12-O-tetradecanoyl phorbol 13-acetate (TPA). The kinetics of induction is characterized by a lag period which differs according to the mitogen used and reflects the length of the G1 phase (4-6 h with insulin or serum, 9-12 h with TPA). The cdc2 mRNA accumulation is prevented when protein synthesis is blocked with cycloheximide, also if the drug is added at a time when the synthesis of cdc2 mRNA is already under way. Similarly, removal of the mitogen leads to a cessation of the cdc2 mRNA accumulation. These results suggest that the increased expression of the cdc2 gene is mediated by (a) short-lived, growth factor-regulated protein(s).
在置于无血清培养基中的化学转化小鼠成纤维细胞（BP - A31）中，cdc2 mRNA含量随着[3H]胸苷掺入的停止而平行下降。在过表达人c - myc癌基因的BP - A31细胞中也观察到cdc2基因表达的消失。在静止期，cdc2基因表达可以用血清或其他有丝分裂原如胰岛素或12 - O - 十四烷酰佛波醇13 - 乙酸酯（TPA）重新诱导。诱导动力学的特征是有一个延迟期，该延迟期根据所用的有丝分裂原而不同，反映了G1期的长度（胰岛素或血清作用下为4 - 6小时，TPA作用下为9 - 12小时）。当用环己酰亚胺阻断蛋白质合成时，即使在cdc2 mRNA合成已经开始时加入该药物，cdc2 mRNA的积累也会被阻止。同样，去除有丝分裂原会导致cdc2 mRNA积累停止。这些结果表明，cdc2基因表达的增加是由一种（或多种）短寿命、受生长因子调节的蛋白质介导的。
